Miniature magneto-ultrasonic machines for wireless robotic sensing and manipulation

Intelligent miniature systems capable of wireless sensing and manipulation hold considerable promise for advancing biomedical applications. However, the development of these systems has been substantially hindered by sensing-actuation incompatibility at small scales. To overcome this challenge, we propose a robotic sensing approach that integrates embedded ultrasonic soft sensors (EUSSs) with magnetic actuators, resulting in a wireless sensor-integrated miniature machine with seamless integration and minimal interference between fields. The EUSS, with its compact dimensions (1.3 millimeters by 1.3 millimeters by 1.6 millimeters), softness (98 kilopascals), and lightweight design (4.6 milligrams), is compatible with both soft and rigid components in terms of deformability and size. By engineering onboard transducers and using passive ultrasound communication along with external magnetic fields, we could wirelessly detect and regulate environmental parameters such as force, vibration, viscosity, and temperature. Demonstrations in rabbit and porcine models show the potential for robotic feedback control, accurate drug dosing, and in situ physiological monitoring, paving the way for real-world applications of intelligent miniature machines.